U.S. patent number 11,082,023 [Application Number 16/576,529] was granted by the patent office on 2021-08-03 for multi-layer raised frame in bulk acoustic wave device.
This patent grant is currently assigned to Skyworks Global Pte. Ltd.. The grantee listed for this patent is Skyworks Global Pte. Ltd.. Invention is credited to Jiansong Liu, Kwang Jae Shin.
United States Patent |
11,082,023 |
Shin , et al. |
August 3, 2021 |
Multi-layer raised frame in bulk acoustic wave device
Abstract
Aspects of this disclosure relate to a bulk acoustic wave device
that includes a multi-layer raised frame structure. The multi-layer
raised frame structure includes a first raised frame layer
positioned between a first electrode and a second electrode of the
bulk acoustic wave device. The first raised frame layer has a lower
acoustic impedance than the first electrode. The first raised frame
layer and the second raised frame layer overlap in an active region
of the bulk acoustic wave device. Related filters, multiplexers,
packaged modules, wireless communication devices, and methods are
disclosed.
Inventors: |
Shin; Kwang Jae (Yongin-si,
KR), Liu; Jiansong (Irvine, CA) |
Applicant: |
Name |
City |
State |
Country |
Type |
Skyworks Global Pte. Ltd. |
Singapore |
N/A |
SG |
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Assignee: |
Skyworks Global Pte. Ltd.
(Singapore, SG)
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Family
ID: |
1000005713320 |
Appl.
No.: |
16/576,529 |
Filed: |
September 19, 2019 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20200099359 A1 |
Mar 26, 2020 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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62735523 |
Sep 24, 2018 |
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62760470 |
Nov 13, 2018 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H03H
9/173 (20130101); H03H 9/13 (20130101); H03H
9/0561 (20130101); H03H 9/564 (20130101); H03H
9/175 (20130101); H03H 9/706 (20130101); H03H
9/02118 (20130101); H03H 9/568 (20130101); H03F
3/189 (20130101); H03F 2200/451 (20130101); H03F
3/20 (20130101); H04B 1/3827 (20130101); H03F
2200/294 (20130101) |
Current International
Class: |
H03H
9/02 (20060101); H03H 9/05 (20060101); H03H
9/56 (20060101); H03H 9/17 (20060101); H03H
9/13 (20060101); H03F 3/189 (20060101); H03H
9/70 (20060101); H03F 3/20 (20060101); H04B
1/3827 (20150101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
Ohara, et al., "Suppression of Acoustic Energy Leakage in FBARs
with A1 Bottom Electrode: FEM Simulation and Experimental Results,"
2007 IEEE Ultrasonics Symposium, pp. 1657-1660. cited by applicant
.
Thalhammer, et al., "Spurious mode suppression in BAW resonators,"
2006 IEEE Ultrasonics Symposium, pp. 456-459. cited by applicant
.
Fattinger, et al., "Optimization of Acoustic Dispersion for High
Performance Thin Film BAW Resonators," 2005 IEEE Ultrasonics
Symposium, pp. 1175-1178. cited by applicant .
Kaitila, et al., "Spurious Resonance Free Bulk Acoustic Wave
Resonators," 2003 IEEE Ultrasonics Symposium. cited by
applicant.
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Primary Examiner: Takaoka; Dean O
Attorney, Agent or Firm: Knobbe, Martens, Olson & Bear,
LLP
Parent Case Text
CROSS REFERENCE TO PRIORITY APPLICATION
This application claims the benefit of priority of U.S. Provisional
Patent Application No. 62/735,523, filed Sep. 24, 2018 and titled
"MULTI-LAYER RAISED FRAME IN BULK ACOUSTIC WAVE DEVICE," and also
claims the benefit of priority of U.S. Provisional Patent
Application No. 62/760,470, filed Nov. 13, 2018 and titled
"MULTI-LAYER RAISED FRAME IN BULK ACOUSTIC WAVE DEVICE," the
disclosures of each of which are hereby incorporated by reference
in their entireties herein.
Claims
What is claimed is:
1. A bulk acoustic wave device comprising: a first electrode; a
second electrode; a piezoelectric layer positioned between the
first electrode and the second electrode; and a multi-layer raised
frame structure outside of a middle area of an active region of the
bulk acoustic wave device, the multi-layer raised frame structure
including a first raised frame layer and a second raised frame
layer, the first raised frame layer being positioned between the
first electrode and the second electrode, the first raised frame
layer having a lower acoustic impedance than the first electrode,
the first raised frame layer being configured to move a frequency
of a raised frame mode away from a main resonant frequency of the
bulk acoustic wave device, and the second raised frame layer
overlapping with the first raised frame layer in the active
region.
2. The bulk acoustic wave device of claim 1 wherein the multi-layer
raised frame structure is configured to block lateral energy
leakage from the active region to a passive region of the bulk
acoustic wave device.
3. The bulk acoustic wave device of claim 1 wherein the acoustic
impedance of the first raised frame layer is lower than an acoustic
impedance of the piezoelectric layer.
4. The bulk acoustic wave device of claim 1 wherein the first
raised frame layer is a silicon dioxide layer.
5. The bulk acoustic wave device of claim 1 wherein the first
electrode includes at least one of molybdenum, tungsten, ruthenium,
platinum, or iridium.
6. The bulk acoustic wave device of claim 1 wherein the first
raised frame layer is positioned between the piezoelectric layer
and the first electrode.
7. The bulk acoustic wave device of claim 1 wherein the first
raised frame layer is disposed in a raised frame domain of the bulk
acoustic wave device along an edge of the active domain.
8. The bulk acoustic wave device of claim 7 wherein the bulk
acoustic wave device further includes a recessed frame domain
between the raised frame domain and the middle area.
9. The bulk acoustic wave device of claim 1 wherein the second
raised frame layer and the piezoelectric layer are disposed on
opposite sides of the second electrode, and the first raised frame
layer is positioned between the piezoelectric layer and the second
electrode.
10. The bulk acoustic wave device of claim 1 wherein the second
raised frame layer has a higher density than the piezoelectric
layer.
11. The bulk acoustic wave device of claim 1 wherein the second
raised frame layer includes the same material as the second
electrode.
12. The bulk acoustic wave device of claim 1 further comprising an
air cavity, the air cavity and the piezoelectric layer being on
opposite sides of the first electrode.
13. The bulk acoustic wave device of claim 1 further comprising an
acoustic Bragg reflector, the acoustic Bragg reflector and the
piezoelectric layer being on opposite sides of the first
electrode.
14. A packaged module comprising: a packaging substrate; an
acoustic wave filter on the packaging substrate and configured to
filter a radio frequency signal, the acoustic wave filter including
a bulk acoustic wave device, the bulk acoustic wave device
including a multi-layer raised frame structure outside of a middle
area of an active region of the bulk acoustic wave device, the
multi-layer raised frame structure including a first raised frame
layer and a second raised frame layer, the first raised frame layer
being positioned between an electrode and a piezoelectric layer,
the first raised frame layer having a lower acoustic impedance than
the electrode, the first raised frame layer being configured to
move a frequency of a raised frame mode away from a main resonant
frequency of the bulk acoustic wave device, and the second raised
frame layer overlapping with the first raised frame layer in the
active region; and a radio frequency component electrically coupled
to the acoustic wave filter and positioned on the packaging
substrate, the acoustic wave filter and the radio frequency
component being enclosed within a common package.
15. The packaged module of claim 14 wherein the radio frequency
component includes at least one of a radio frequency amplifier or a
radio frequency switch.
16. The packaged module of claim 14 wherein the multi-layer raised
frame structure is disposed in a raised frame domain of the bulk
acoustic wave device, and the bulk acoustic wave device includes a
recessed frame domain between the raised frame domain and the
middle area of the active region of the bulk acoustic wave
device.
17. A bulk acoustic wave device comprising: a first electrode; a
second electrode; a piezoelectric layer positioned between the
first electrode and the second electrode; and a multi-layer raised
frame structure including a first raised frame layer and a second
raised frame layer, the first raised frame layer being positioned
between the first electrode and the second electrode, the first
raised frame layer having a lower acoustic impedance than the
second raised frame layer, the first raised frame layer being
configured to move a frequency of a raised frame mode away from a
main resonant frequency of the bulk acoustic wave device, and the
second raised frame layer overlapping with the first raised frame
layer.
18. The bulk acoustic wave device of claim 17 wherein the
multi-layer raised frame structure is disposed in a raised frame
domain of the bulk acoustic wave device, and the bulk acoustic wave
device includes a recessed frame domain between the raised frame
domain and a middle area of the bulk acoustic wave device.
19. The bulk acoustic wave device of claim 18 further comprising a
passivation layer over the first electrode, the passivation layer
being thinner in the recessed frame domain than in the middle area
of the bulk acoustic wave device.
20. The bulk acoustic wave device of claim 18 wherein the first
electrode is thinner in the recessed frame domain than in the
middle area of the bulk acoustic wave device.
21. The bulk acoustic wave device of claim 17 wherein the first
raised frame layer includes silicon dioxide.
22. The bulk acoustic wave device of claim 17 wherein the first
electrode is positioned between the second raised frame layer and
the piezoelectric layer.
Description
BACKGROUND
Technical Field
Embodiments of this disclosure relate to acoustic wave devices and,
more specifically, to bulk acoustic wave devices.
Description of Related Technology
Acoustic wave filters can be implemented in radio frequency
electronic systems. For instance, filters in a radio frequency
front end of a mobile phone can include one or more acoustic wave
filters. A plurality of acoustic wave filters can be arranged as a
multiplexer. For instance, two acoustic wave filters can be
arranged as a duplexer.
An acoustic wave filter can include a plurality of resonators
arranged to filter a radio frequency signal. Example acoustic wave
filters include surface acoustic wave (SAW) filters and bulk
acoustic wave (BAW) filters. BAW filters include BAW resonators.
Example BAW resonators include film bulk acoustic wave resonators
(FBARs) and solidly mounted resonators (SMRs). In BAW resonators,
acoustic waves propagate in a bulk of a piezoelectric layer.
For high performance BAW filters, low insertion loss and low Gamma
loss is generally desirable. However, desired levels of insertion
loss and Gamma loss can be difficult to achieve.
SUMMARY OF CERTAIN INVENTIVE ASPECTS
The innovations described in the claims each have several aspects,
no single one of which is solely responsible for its desirable
attributes. Without limiting the scope of the claims, some
prominent features of this disclosure will now be briefly
described.
One aspect of this disclosure is a bulk acoustic wave device that
includes a first electrode, a second electrode, a piezoelectric
layer positioned between the first electrode and the second
electrode, and a multi-layer raised frame structure outside of a
middle area of an active region of the bulk acoustic wave device.
The multi-layer raised frame structure includes a first raised
frame layer and a second raised frame layer. The first raised frame
layer is positioned between the first electrode and the second
electrode. The first raised frame layer has a lower acoustic
impedance than the first electrode. The second raised frame layer
overlaps with the first raised frame layer in the active
region.
The first raised frame layer can move a frequency of a raised frame
mode away from a main resonant frequency of the bulk acoustic wave
device. The acoustic impedance of the first raised frame layer can
be lower than an acoustic impedance of the piezoelectric layer. The
first raised frame layer can be a silicon dioxide layer. The first
raised frame layer can be positioned between the piezoelectric
layer and the first electrode. The first raised frame layer can be
disposed in a raised frame domain of the bulk acoustic wave device
along an edge of the active domain. The bulk acoustic wave device
can further include a recessed frame domain between the raised
frame domain and the middle area.
The multi-layer raised frame structure can block lateral energy
leakage from the active region to a passive region of the bulk
acoustic wave device.
The first electrode can include molybdenum. The first electrode can
include tungsten. The first electrode can include ruthenium. The
first electrode can include platinum. The first electrode can
include iridium. The first electrode can include any suitable alloy
of molybdenum, tungsten, ruthenium, platinum, and/or iridium.
The second raised frame layer and the piezoelectric layer can be
disposed on opposite sides of the second electrode. The first
raised frame layer can be positioned between the piezoelectric
layer and the second electrode. The second raised frame layer can
have a higher density than the piezoelectric layer. The second
raised frame layer includes the same material as the second
electrode. The second raised frame layer can also include the same
material as the first electrode.
The bulk acoustic wave device can include a passivation layer over
the multi-layer raised frame layer. The bulk acoustic wave device
can include a silicon dioxide layer over the multi-layer raised
frame layer.
The bulk acoustic wave device can include an air cavity, in which
the air cavity and the piezoelectric layer are on opposite sides of
the first electrode.
The bulk acoustic wave device can include an acoustic Bragg
reflector, in which the acoustic Bragg reflector and the
piezoelectric layer are on opposite sides of the first
electrode.
Another aspect of this disclosure is a multiplexer that includes a
first filter having a first passband and a second filter having a
second passband. The first filter includes a bulk acoustic wave
device. The bulk acoustic wave device includes a multi-layer raised
frame structure outside of a middle area of an active region of the
bulk acoustic wave device. The multi-layer raised frame structure
includes a first raised frame layer and a second raised frame
layer. The first raised frame layer is positioned between an
electrode and a piezoelectric layer. The first raised frame layer
has a lower acoustic impedance than the electrode. The second
raised frame layer overlaps with the first raised frame layer in
the active region. The second filter is coupled to the first
acoustic wave filter at a common node. The multi-layer raised frame
structure is configured to move a raised frame mode of the bulk
acoustic wave device away from the second passband.
The acoustic impedance of the first raised frame layer can be lower
than an acoustic impedance of the piezoelectric layer. The first
acoustic filter can further include a second bulk acoustic wave
device, in which the second bulk acoustic wave device includes a
second multi-layer raised frame structure outside of a middle area
of an active region of the second bulk acoustic wave device.
The second filter can be an acoustic wave filter. The multiplexer
can include one or more additional filters coupled to the common
node.
The common node can receive a carrier aggregation signal including
at least a first carrier associated with the first passband and a
second carrier associated with the second passband.
The multi-layer raised frame mode can cause a reflection
coefficient of the first acoustic wave filter in the second
passband to be increased.
Another aspect of this disclosure is a packaged module that
includes a packaging substrate, an acoustic wave filter on the
packaging substrate and configured to filter a radio frequency
signal, and a radio frequency component electrically coupled to the
acoustic wave filter and positioned on the packaging substrate. The
acoustic wave filter and the radio frequency component are enclosed
within a common package. The acoustic wave filter includes a bulk
acoustic wave device. The bulk acoustic wave device includes a
multi-layer raised frame structure outside of a middle area of an
active region of the bulk acoustic wave device. The multi-layer
raised frame structure includes a first raised frame layer and a
second raised frame layer. The first raised frame layer is
positioned between an electrode and a piezoelectric layer. The
first raised frame layer has a lower acoustic impedance than the
electrode. The second raised frame layer overlap with the first
raised frame layer in the active region.
The radio frequency component can includes a radio frequency
amplifier, such as a power amplifier or a low noise amplifier. The
radio frequency component can include a radio frequency switch.
Another aspect of this disclosure is a bulk acoustic wave device
that includes a first electrode, a second electrode, a
piezoelectric layer positioned between the first electrode and the
second electrode, and a multi-layer raised frame structure outside
of a middle area of an active region of the bulk acoustic wave
device. The multi-layer raised frame structure includes a first
raised frame layer and a second raised frame layer. The first
raised frame layer is positioned between the first electrode and
the second electrode. The first raised frame layer has a lower
acoustic impedance than the piezoelectric layer. The second raised
frame layer overlaps with the first raised frame layer in the
active region.
The first raised frame layer can move a frequency of a raised frame
mode away from a main resonant frequency of the bulk acoustic wave
device. The first raised frame layer can be a silicon dioxide
layer. The first raised frame layer can be positioned between the
piezoelectric layer and the first electrode. The first raised frame
layer can be disposed in a raised frame domain of the bulk acoustic
wave device along an edge of the active domain. The bulk acoustic
wave device can further include a recessed frame domain between the
raised frame domain and the middle area.
The multi-layer raised frame structure can block lateral energy
leakage from the active region to a passive region of the bulk
acoustic wave device.
The first electrode can include molybdenum. The first electrode can
include tungsten. The first electrode can include ruthenium.
The second raised frame layer and the piezoelectric layer can be
disposed on opposite sides of the second electrode. The first
raised frame layer can be positioned between the piezoelectric
layer and the second electrode. The second raised frame layer can
have a higher density than the piezoelectric layer. The second
raised frame layer includes the same material as the second
electrode. The second raised frame layer can also include the same
material as the first electrode.
The bulk acoustic wave device can include a passivation layer over
the multi-layer raised frame layer. The bulk acoustic wave device
can include a silicon dioxide layer over the multi-layer raised
frame layer.
The bulk acoustic wave device can include an air cavity, in which
the air cavity and the piezoelectric layer are on opposite sides of
the first electrode.
The bulk acoustic wave device can include an acoustic Bragg
reflector, in which the acoustic Bragg reflector and the
piezoelectric layer are on opposite sides of the first
electrode.
The bulk acoustic wave device can be included in any suitable
filter, multiplexer and/or module disclosed herein.
For purposes of summarizing the disclosure, certain aspects,
advantages and novel features of the innovations have been
described herein. It is to be understood that not necessarily all
such advantages may be achieved in accordance with any particular
embodiment. Thus, the innovations may be embodied or carried out in
a manner that achieves or optimizes one advantage or group of
advantages as taught herein without necessarily achieving other
advantages as may be taught or suggested herein.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of this disclosure will now be described, by way of
non-limiting example, with reference to the accompanying
drawings.
FIG. 1 is a plan view of a dual raised frame bulk acoustic wave
device.
FIG. 2 is a cross sectional view of a dual raised frame bulk
acoustic wave device according to an embodiment.
FIG. 3 is a cross sectional view of a dual raised frame bulk
acoustic wave device according to another embodiment.
FIG. 4 is a cross sectional view of a dual raised frame bulk
acoustic wave device according to another embodiment.
FIG. 5 is a cross sectional view of a dual raised frame bulk
acoustic wave device according to another embodiment.
FIG. 6 is a cross sectional view of a dual raised frame bulk
acoustic wave device according to another embodiment.
FIG. 7A is a cross sectional view of a dual raised frame bulk
acoustic wave device according to another embodiment.
FIG. 7B is a cross sectional view of a dual raised frame bulk
acoustic wave device according to another embodiment.
FIG. 8 is a cross sectional view of a dual raised frame bulk
acoustic wave device according to another embodiment.
FIG. 9 is a cross sectional view of a dual raised frame bulk
acoustic wave device according to another embodiment.
FIG. 10A is a cross sectional view of a raised frame bulk acoustic
wave device.
FIG. 10B is a cross sectional view of another raised frame bulk
acoustic wave device.
FIG. 10C is a cross sectional view of a dual raised frame bulk
acoustic wave device according to an embodiment.
FIG. 11A is a graph that compares quality factor for the bulk
acoustic wave devices of FIGS. 10A, 10B, and 10C.
FIG. 11B is a graph that compares conductance for the bulk acoustic
wave devices of FIGS. 10A, 10B, and 10C over a larger frequency
range than for FIG. 11A.
FIG. 12 is a schematic diagram of an example of an acoustic wave
ladder filter.
FIG. 13A is a schematic diagram of an example of a duplexer.
FIG. 13B is a schematic diagram of an example of a multiplexer.
FIG. 14 is a schematic block diagram of a module that includes an
antenna switch and duplexers that include one or more multi-layer
raised frame bulk acoustic wave devices.
FIG. 15A is a schematic block diagram of a module that includes a
power amplifier, a radio frequency switch, and duplexers that
include one or more multi-layer raised frame bulk acoustic wave
devices.
FIG. 15B is a schematic block diagram of a module that includes a
low noise amplifier, a radio frequency switch, and acoustic wave
filters t include one or more multi-layer raised frame bulk
acoustic wave devices.
FIG. 16 is a schematic block diagram of a module that includes a
power amplifier, a radio frequency switch, a duplexer that includes
one or more multi-layer raised frame bulk acoustic wave
devices.
FIG. 17A is a schematic block diagram of a wireless communication
device that includes filters that include one or more multi-layer
raised frame bulk acoustic wave devices.
FIG. 17B is a schematic block diagram of another wireless
communication device that includes filters that include one or more
multi-layer raised frame bulk acoustic wave devices.
DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS
The following description of certain embodiments presents various
descriptions of specific embodiments. However, the innovations
described herein can be embodied in a multitude of different ways,
for example, as defined and covered by the claims. In this
description, reference is made to the drawings where like reference
numerals can indicate identical or functionally similar elements.
It will be understood that elements illustrated in the figures are
not necessarily drawn to scale. Moreover, it will be understood
that certain embodiments can include more elements than illustrated
in a drawing and/or a subset of the elements illustrated in a
drawing. Further, some embodiments can incorporate any suitable
combination of features from two or more drawings.
For developing high performance bulk acoustic wave (BAW) filters,
reducing insertion loss and decreasing Gamma loss is generally
desirable. To achieve a low insertion loss, BAW resonators
typically have a high quality factor (Q). To achieve a high Q, a
raised frame, which can be referred to as a border ring, can block
lateral energy leakage from an active domain of a BAW resonator to
a passive domain of the BAW resonator. A raised frame can improve
Q, although it may not be able to trap all leakage energy. The
raised frame can generate a relatively large spurious mode, which
can be referred to as raised frame mode, below a main resonant
frequency of a BAW resonator. This can cause Gamma degradation in
carrier aggregation bands for a filter. Gamma can refer to a
reflection coefficient. A low Gamma loss can be achieved with a
raised frame spurious mode (RaF mode) away from carrier aggregation
bands.
Aspects of this disclosure relate to a bulk acoustic wave resonator
that includes a multi-layer raised frame structure that can achieve
low insertion loss and low Gamma loss. The multi-layer raised frame
structure includes a first raised frame layer and a second raised
frame layer. The first raised frame layer includes a low acoustic
impedance material, such as silicon dioxide, disposed between
electrodes that are on opposing sides of a piezoelectric layer. For
instance, the low acoustic impedance material can be disposed
between a top electrode and a piezoelectric layer of a bulk
acoustic wave resonator. The multi-layer raised frame structure can
be disposed along a perimeter of an active region of the bulk
acoustic wave resonator. The second raised frame layer can include
a relatively heavy material. The second raised frame layer can be
the same material as an electrode of the bulk acoustic wave
resonator.
Due to a low acoustic impedance, the frequency of a multi-layer
raised frame domain generating a relatively strong raised frame
spurious mode can be significantly lower than for a similar raised
frame domain without the first raised frame layer with a low
acoustic impedance. With the low acoustic impedance, the raised
frame mode for the multi-layer raised frame structure can be
outside of a carrier aggregation band so as not to provide a Gamma
loss. For example, in a carrier aggregation application, a
multiplexer can include a common node arranged to receive a carrier
aggregation signal, a first filter having a passband associated
with a first carrier of the carrier aggregation signal, and a
second filter coupled to the first filter at the common node and
having a second passband associated with a second carrier of the
carrier aggregation signal. The first filter can include a BAW
resonator with a multi-layer raised frame structure according to an
embodiment disclosed herein. The BAW resonator with the multi-layer
raised frame structure can increase Gamma for the first filter in
the passband of the second filter.
Additionally, due to a relatively low frequency of the multi-layer
raised frame structure, the difference between the effective
acoustic impedance of the multi-layer raised frame domain and the
active domain is larger than for a raised frame structure that
includes a single layer corresponding to the second raised frame
layer. The multi-layer raised frame structure can provide a high
mode reflection of a lateral energy and decrease mode conversion
from main mode to other lateral modes around the anti-resonance
frequency. Accordingly, Q can be significantly increased.
Although embodiments disclosed herein may be discussed with
reference to a dual raised frame structure with two raised frame
layers, any suitable principles and advantages discussed herein can
be applied to a multi-layer raised frame structure that includes
two or more raised frame layers.
Example bulk acoustic resonators with dual raised frame layers will
now be discussed. Any suitable principles and advantages of these
dual raised frame layers can be implemented together with each
other in a multi-layer raised frame bulk acoustic wave device.
FIG. 1 is a plan view of a dual raised frame bulk acoustic wave
device. As shown in FIG. 1, the bulk acoustic wave device includes
a raised frame zone 12 around the perimeter of an active region of
the bulk acoustic wave device. The raised frame zone 12 can be
referred to as a border ring in certain instances. A dual raised
frame structure can be in the raised frame zone 12. The dual raised
frame structure can be implemented in accordance with any suitable
principles and advantages of the dual raised frame bulk acoustic
wave devices of FIGS. 2 to 9. The dual raised frame structure is
outside of a middle area 14 of the active region of the bulk
acoustic wave device. A raised frame layer can be in the raised
frame zone 12 and extend above a metal electrode. FIG. 1
illustrates the metal electrode of the middle area 14 and the
raised frame layer in the raised frame zone 12. One or more other
layers can be included over the metal electrode and the raised
frame layer. For instance, silicon dioxide can be included over the
metal electrode and the raised frame layer. FIG. 1 also illustrates
that a piezoelectric layer 16 of the bulk acoustic wave device is
below the metal electrode and the raised frame layer.
Embodiments of dual raised frame bulk acoustic wave devices will be
discussed with reference to example cross sections along the line
from A to A' of FIG. 1. FIGS. 2 to 9 illustrate example cross
sections of dual raised frame bulk acoustic wave devices along the
line from A to A' in FIG. 1. Any suitable combination of features
of the bulk acoustic wave devices of FIGS. 2 to 9 can be combined
with each other. Any of the bulk acoustic wave devices disclosed
herein can be a bulk acoustic wave resonators in a filter arranged
to filter a radio frequency signal.
FIG. 2 is a cross sectional view of a dual raised frame bulk
acoustic wave device 20 according to an embodiment. As illustrated,
the dual raised frame bulk acoustic device 20 includes a
piezoelectric layer 16, a first electrode 21, a second electrode
22, a first raised frame layer 23, a second raised frame layer 24,
a silicon substrate 25, an air cavity 26, and a silicon dioxide
layer 27.
The piezoelectric layer 16 is disposed between the first electrode
21 and the second electrode 22. The piezoelectric layer 16 can be
an aluminum nitride (AlN) layer or any other suitable piezoelectric
layer. An active region or active domain of the bulk acoustic wave
device 20 is defined by the portion of the piezoelectric layer 16
that overlaps with both the first electrode 21 and the second
electrode 22. The first electrode 21 can have a relatively high
acoustic impedance. For example, the first electrode 21 can include
molybdenum (Mo), tungsten (W), ruthenium (Ru), iridium (Ir),
platinum (Pt), Ir/Pt, or any suitable alloy and/or combination
thereof. Similarly, the second electrode 22 can have a relatively
high acoustic impedance. The second electrode 22 can be formed of
the same material as the first electrode 21 in certain
instances.
The dual raised frame structure of the bulk acoustic wave device 20
includes the first raised frame layer 23 and the second raised
frame layer 24. The first raised frame layer 23 and the second
raised frame layer 24 overlap with each other in the active region
of the bulk acoustic wave device 20. A raised frame domain of the
bulk acoustic wave device 20 is defined by the portion of dual
raised frame structure in the active domain of the bulk acoustic
wave device 20. At least a portion of the dual raised frame
structure is included in an active region of the bulk acoustic wave
device 20. The dual raised frame structure can improve Q
significantly due to highly efficient reflection of lateral
energy.
The first raised frame layer 23 is positioned between the first
electrode 21 and the second electrode 22. As illustrated in FIG. 2,
the first raised frame layer 23 is positioned between the
piezoelectric layer 16 and the second electrode 22. The first
raised frame layer 23 is a low acoustic impedance material. The low
acoustic impedance material has a lower acoustic impedance than the
first electrode 21. The low acoustic impedance material has a lower
acoustic impedance than the second electrode 22. The low acoustic
impedance material can have a lower acoustic impedance than the
piezoelectric layer 16. As an example, the first raised frame layer
23 can be a silicon dioxide (SiO.sub.2) layer. Because silicon
dioxide is already used in a variety of bulk acoustic wave devices,
a silicon dioxide first raised frame layer 23 can be relatively
easy to manufacture. The first raised frame layer 23 can be a
silicon nitride (SiN) layer, a silicon carbide (SiC) layer, or any
other suitable low acoustic impedance layer. The first raised frame
layer 23 can have a relatively low density. The first raised frame
layer 23 can extend beyond the active region of the bulk acoustic
wave device 20 as shown in FIG. 2. This can be for
manufacturability reasons in certain instances.
The first raised frame layer 23 can reduce an effective
electromechanical coupling coefficient (k.sup.2) of the raised
frame domain of the bulk acoustic wave device 20 relative to a
similar device without the first raised frame layer 23. This can
reduce excitation strength of a raised frame spurious mode.
Moreover, the first raised frame layer 23 can contribute to move
the frequency of the raised frame mode relatively far away from the
main resonant frequency of the bulk acoustic wave device 20, which
can result in no significant effect on a Gamma loss.
As illustrated, the second raised frame layer 24 overlaps with the
first raised frame layer 23 in the active region of the bulk
acoustic wave device 20. The second raised frame layer 24 can be
the same material as the second electrode 22. This can be
convenient from a manufacturing perspective. The second raised
frame layer 24 can be a relatively high density material. For
instance, the second raised frame layer 24 can include molybdenum
(Mo), tungsten (W), ruthenium (Ru), the like, or any suitable alloy
thereof. The second raised frame layer 24 can be a metal layer.
Alternatively, the second raised frame layer 24 can be a suitable
non-metal material with a relatively high density. The density of
the second raised frame layer 24 can be similar or heavier than the
density of the second electrode 22. The second raised frame layer
24 can have a relatively high acoustic impedance.
The second raised frame layer 24 increases the height of the bulk
acoustic wave device 20 in the raised frame domain. Accordingly,
the bulk acoustic wave device 20 has a greater height in the raised
frame domain than in other portions of the active domain, such as
the middle area of the active domain. Forming the second raised
frame layer 24 over the second electrode 22 can be relatively easy
from a manufacturing perspective. However, in some other
embodiments, a second raised frame layer can be included in a
different position in the stack of layers in the raised frame
domain.
In the bulk acoustic wave device 20, a silicon dioxide layer 27 is
included over the second electrode 22 and the second raised frame
layer 24. The silicon dioxide layer 27 can be formed with different
thicknesses in different regions of the bulk acoustic wave device
20. For example, as shown in FIG. 2, the silicon dioxide layer 27
is thinner in a recessed frame domain. Any suitable passivation
layer can be included in place and/or in addition to the silicon
dioxide layer 27.
The dual raised frame bulk acoustic wave device 20 is an FBAR. An
air cavity 26 is included below the first electrode 21. The air
cavity 26 is defined by the geometry of the first electrode 21 and
the silicon substrate 25. Other suitable substrates can
alternatively be implemented in place of the silicon substrate 25.
One or more layers, such as a passivation layer, can be positioned
between the first electrode 21 and the silicon substrate 25.
Although the bulk acoustic wave device 20 is an FBAR, any suitable
principles and advantages discussed herein can be applied to a
solidly mounted resonator (SMR).
FIG. 3 is a cross sectional view of a dual raised frame bulk
acoustic wave device 30 according to an embodiment. The dual raised
frame bulk acoustic device 30 is like the dual raised frame bulk
acoustic wave device 20 of FIG. 2, except that the bulk acoustic
wave device 30 is an SMR instead of an FBAR. In the bulk acoustic
wave device 30, a solid acoustic mirror is disposed between the
first electrode 21 and a silicon substrate 35. The illustrated
acoustic mirror includes acoustic Bragg reflectors 32. The
illustrated acoustic Bragg reflectors 32 include alternating low
impedance layers 33 and high impedance layers 34. As an example,
the Bragg reflectors 32 can include alternating silicon dioxide
layers as low impedance layers 33 and tungsten layers as high
impedance layers 34. Any other suitable features of an SMR can
alternatively or additionally be implemented in a multi-layer
raised frame bulk acoustic wave device.
FIG. 4 is a cross sectional view of a dual raised frame bulk
acoustic wave device 40 according to an embodiment. The dual raised
frame bulk acoustic device 40 is like the dual raised frame bulk
acoustic wave device 20 of FIG. 2, except that the silicon dioxide
layer 27 is omitted in the bulk acoustic wave device 40 and there
is no recessed framed domain in the bulk acoustic wave device
40.
FIG. 5 is a cross sectional view of a dual raised frame bulk
acoustic wave device 50 according to an embodiment. The dual raised
frame bulk acoustic device 50 is like the dual raised frame bulk
acoustic wave device 40 of FIG. 4, except that the first raised
frame layer 53 of the bulk acoustic wave device 50 is different
than the first raised frame layer 23 of the bulk acoustic wave
device 40. As illustrated in FIG. 5, the first raised frame layer
53 spans the raised frame domain. The first raised frame layer 53
does not extend beyond the active region of the bulk acoustic wave
device 50.
FIG. 6 is a cross sectional view of a dual raised frame bulk
acoustic wave device 60 according to an embodiment. The dual raised
frame bulk acoustic device 60 is like the dual raised frame bulk
acoustic wave device 40 of FIG. 4, except that a second electrode
62 of the bulk acoustic wave device 60 is different than the second
electrode 22 of the bulk acoustic wave device 40. The second
electrode 62 has different thicknesses in different regions. The
region where the second electrode 62 is thinner implements a
recessed framed domain in the bulk acoustic wave device 60.
FIG. 7A is a cross sectional view of a dual raised frame bulk
acoustic wave device 70 according to an embodiment. The dual raised
frame bulk acoustic device 70 is like the dual raised frame bulk
acoustic wave device 40 of FIG. 4, except that the bulk acoustic
wave device 70 includes two raised frame domains. The bulk acoustic
wave device 70 includes a first raised frame layer 73 in a first
raised frame domain RaF and a second raised frame domain RaF3. The
first raised frame domain RaF in the bulk acoustic wave device 70
is like the raised frame domain in the bulk acoustic wave device 40
of FIG. 4. The first raised frame layer 73 and the second raised
frame layer 24 are included in the first raise frame domain RaF.
The first raised frame layer 73 can include any suitable features
of the first raised frame layer 23 of FIG. 2. The first raised
frame layer 73 is thinner in the second raised frame domain RaF3 in
which the first raised frame layer 73 and a second electrode 72 are
over the piezoelectric layer 16.
The second raised frame region RaF3 can be referred to as a
recessed raised frame region. The second electrode 72 has a
different shape in cross sectional view than the second electrode
22 of FIG. 4. The second raised frame layer 24 is outside of the
second raised frame domain RaF3. With the first raised frame layer
73, the second raised frame domain RaF3 has a different acoustic
impedance than (1) the middle area of the active region and (2) the
first raised frame domain. This can help with spurious mode
suppression. The first raised frame region can surround the second
raised frame region in plan view in the bulk acoustic wave device
70.
FIG. 7B is a cross sectional view of a dual raised frame bulk
acoustic wave device 75 according to an embodiment. The dual raised
frame bulk acoustic device 75 is like the dual raised frame bulk
acoustic wave device 70 of FIG. 7A, except that the bulk acoustic
wave device 75 includes a second raised frame layer 77 that extends
over two raised frame domains. As illustrated in FIG. 7B, the
second raised frame layer 77 is included in a first raised frame
domain RaF and a second raised frame domain RaF3. The first raised
frame layer 73 is thinner in the second raised frame domain of the
bulk acoustic wave device 75. The second raised frame layer 77 has
substantially the same thickness over both the first raised frame
domain RaF and the second raised frame domain RaF3 in the bulk
acoustic wave device 75. The two raised frame domains in the bulk
acoustic wave device 75 can help with spurious mode
suppression.
FIG. 8 is a cross sectional view of a dual raised frame bulk
acoustic wave device 80 according to an embodiment. The dual raised
frame bulk acoustic device 80 is like the dual raised frame bulk
acoustic wave device 50 of FIG. 5, except that the first raised
frame layer is in different positions in these devices. In the bulk
acoustic wave device 80, a first raised frame layer 83 is
positioned between the first electrode 21 and a piezoelectric layer
86. The first raised frame layer 83 is in physical contact with the
piezoelectric layer 86 and the first electrode 21. The first raised
frame layer 83 can function similarly to the first raised frame
layer 23. The first raised frame layer 83 can include any suitable
features of the first raised frame layer 23. The piezoelectric
layer 86 has a different shape in cross sectional view than the
piezoelectric layer 16 of FIG. 5.
FIG. 9 is a cross sectional view of a dual raised frame bulk
acoustic wave device 90 according to an embodiment. The dual raised
frame bulk acoustic device 90 is like the dual raised frame bulk
acoustic wave device 80 of FIG. 8, except that the second electrode
and piezoelectric layer have different shapes in cross sectional
view. As shown in FIG. 9, a second electrode 92 can have a planar
top surface on which the second raised frame layer 24 is disposed.
The planar top surface can make manufacturing easier in certain
instances.
As discussed above, dual raised frame bulk acoustic wave devices
discussed herein can have improved Q relative to single layer
raised frame devices. FIGS. 10A to 10C illustrate raised frame bulk
acoustic wave devices including single raised frame bulk acoustic
wave devices and a dual raised frame bulk acoustic wave device.
FIGS. 11A to 11B are graphs comparing Q of the raised frame bulk
acoustic wave devices of FIGS. 10A to 10C.
FIG. 10A is a cross sectional view of a raised frame bulk acoustic
wave device 100. The raised frame bulk acoustic wave device 100
includes a single layer raised frame structure. The raised frame
structure of the bulk acoustic wave device 100 includes the raised
frame layer 23.
FIG. 10B is a cross sectional view of a raised frame bulk acoustic
wave device 104. The raised frame bulk acoustic wave device 104
includes a single layer raised frame structure. The raised frame
structure of the bulk acoustic wave device 104 includes the raised
frame layer 24.
FIG. 10C is a cross sectional view of a raised frame bulk acoustic
wave device 108. The raised frame bulk acoustic wave device 108
includes a dual layer raised frame structure that includes both the
raised frame layer 23 and the raised frame layer 24.
FIG. 11A is a graph that compares Q for the bulk acoustic wave
devices 100, 104, and 108 of FIGS. 10A, 10B, and 10C, respectively.
The bulk acoustic wave device 108 can provide better reflection of
lateral energy than the bulk acoustic wave devices 104 and 108.
FIG. 11A illustrates that the bulk acoustic wave device 108 can
achieve a higher Q than the bulk acoustic wave devices 100 and
104.
FIG. 11B is a graph that compares conductance in decibels (dB) for
the bulk acoustic wave devices 100, 104, and 108 of FIGS. 10A, 10B,
and 10C, respectively, over a larger frequency range than for FIG.
11A. FIG. 11B illustrates that the bulk acoustic wave device 104
has relatively large noise at a frequency difference F.sub.D3 from
a resonant frequency, the bulk acoustic wave device 100 has
relatively large noise at a frequency difference F.sub.D2 from the
resonant frequency, and the bulk acoustic wave device 108 has
relatively large noise at a frequency difference F.sub.D1 from a
resonant frequency. The relatively large noise for these bulk
acoustic devices at these frequency differences correspond to
raised frame spurious modes. As shown in FIG. 11B, the frequency
differences satisfy the following relationship:
F.sub.D1>F.sub.D2>F.sub.D3. The frequency difference F.sub.D3
can be closer to the resonant frequency that desired for various
applications. For instance, in the context of a multiplexer, the
noise at the frequency difference F.sub.D3 away from the resonant
frequency can affect performance of a neighboring filter.
FIG. 11B indicates that the bulk acoustic wave device 108 has a
raised frame spurious mode that is farther from the resonant
frequency than the raised frame spurious modes of the bulk acoustic
wave devices 100 and 104. As shown in FIG. 11B, there is almost 1
gigahertz (GHz) separation between the raised frame spurious mode
and the resonant frequency for the bulk acoustic wave device 108.
Accordingly, such a raised frame spurious mode should not affect
other acoustic wave filters (e.g., one or more other acoustic wave
filters of a multiplexer) arranged to filter a radio frequency
signal having a frequency similar to the resonant frequency of the
bulk acoustic wave device 108. This can be advantageous in carrier
aggregation applications, for example.
FIG. 11B indicates that the bulk acoustic wave device 108 has a
raised frame spurious mode with a lower magnitude than the raised
frame spurious modes of the bulk acoustic wave devices 100 and
104.
The multi-layer raised frame bulk acoustic wave resonators
disclosed herein can be implemented in acoustic wave filters. In
certain applications, the acoustic wave filters can be band pass
filters arranged to pass a radio frequency band and attenuate
frequencies outside of the radio frequency band. Two or more
acoustic wave filters can be coupled together at a common node and
arranged as a multiplexer, such as a duplexer.
FIG. 12 is a schematic diagram of an example of an acoustic wave
ladder filter 120. The acoustic wave ladder filter 120 can be a
transmit filter or a receive filter. The acoustic wave ladder
filter 120 can be a band pass filter arranged to filter a radio
frequency signal. The acoustic wave filter 120 includes series
resonators R1, R3, R5, R7, and R9 and shunt resonators R2, R4, R6,
and R8 coupled between a radio frequency input/output port
RF.sub.I/O and an antenna port ANT. The radio frequency
input/output port RF.sub.I/O can be a transmit port in a transmit
filter or a receive port in a receive filter. One or more of the
illustrated acoustic wave resonators can be a multi-layer raised
frame bulk acoustic wave resonator in accordance with any suitable
principles and advantages discussed herein. A acoustic wave ladder
filter can include any suitable number of series resonators and any
suitable number of shunt resonators.
A acoustic wave filter can be arranged in any other suitable filter
topology, such as a lattice topology or a hybrid ladder and lattice
topology. A bulk acoustic wave resonator in accordance with any
suitable principles and advantages disclosed herein can be
implemented in a band pass filter. In some other applications, a
bulk acoustic wave resonator in accordance with any suitable
principles and advantages disclosed herein can be implemented in a
band stop filter.
FIG. 13A is a schematic diagram of an example of a duplexer 130.
The duplexer 130 includes a transmit filter 131 and a receive
filter 132 coupled to each other at an antenna node ANT. A shunt
inductor L1 can be connected to the antenna node ANT. The transmit
filter 131 and the receive filter 132 are both acoustic wave ladder
filters in the duplexer 130.
The transmit filter 131 can filter a radio frequency signal and
provide a filtered radio frequency signal to the antenna node ANT.
A series inductor L2 can be coupled between a transmit input node
TX and the acoustic wave resonators of the transmit filter 131. The
illustrated transmit filter 131 includes acoustic wave resonators
T01 to T09. One or more of these resonators can be a multi-layer
raised frame bulk acoustic wave resonator in accordance with any
suitable principles and advantages disclosed herein. The
illustrated receive filter includes acoustic wave resonators R01 to
R09. One or more of these resonators can be a multi-layer raised
frame bulk acoustic wave resonator in accordance with any suitable
principles and advantages disclosed herein. The receive filter can
filter a radio frequency signal received at the antenna node ANT. A
series inductor L3 can be coupled between the resonator and a
receive output node RX. The receive output node RX of the receive
filter provides a radio frequency receive signal.
FIG. 13B is a schematic diagram of a multiplexer 135 that includes
an acoustic wave filter according to an embodiment. The multiplexer
135 includes a plurality of filters 136A to 136N coupled together
at a common node COM. The plurality of filters can include any
suitable number of filters including, for example, 3 filters, 4
filters, 5 filters, 6 filters, 7 filters, 8 filters, or more
filters. Some or all of the plurality of acoustic wave filters can
be acoustic wave filters. Each of the illustrated filters 136A,
136B, and 136N is coupled between the common node COM and a
respective input/output node RF.sub.I/O1, RF.sub.I/O2, and
RF.sub.I/ON.
In some instances, all filters of the multiplexer 135 can be
receive filters. According to some other instances, all filters of
the multiplexer 135 can be transmit filters. In various
applications, the multiplexer 135 can include one or more transmit
filters and one or more receive filters. Accordingly, the
multiplexer 135 can include any suitable number of transmit filters
and any suitable number of receive filters. Each of the illustrated
filters can be band pass filters having different respective pass
bands.
The multiplexer 135 is illustrated with hard multiplexing with the
filters 136A to 136N having fixed connections to the common node
COM. In some other applications, one or more of the filters of a
multiplexer can be electrically connected to the common node by a
respective switch. Any of such filters can include a bulk acoustic
wave resonator according to any suitable principles and advantages
disclosed herein.
A first filter 136A is an acoustic wave filter having a first pass
band and arranged to filter a radio frequency signal. The first
filter 136A can include one or more bulk acoustic wave resonators
according to any suitable principles and advantages disclosed
herein. A second filter 136B has a second pass band. A multi-layer
raised frame structure of one or more bulk acoustic wave resonators
of the first filter 136A can move a raised frame mode of the one or
more bulk acoustic wave resonators away from the second passband.
This can increase a reflection coefficient (Gamma) of the first
filter 136A in the pass band of the second filter 136B. The
multi-layer raised frame structure of the bulk acoustic wave
resonator of the first filter 136A also move the raised frame mode
away from the passband of one or more other filters of the
multiplexer 135.
In certain instances, the common node COM of the multiplexer 135 is
arranged to receive a carrier aggregation signal including at least
a first carrier associated with the first passband of the first
filter 136A and a second carrier associated with the second
passband of the second filter 136B. A multi-layer raised frame
structure of a bulk acoustic wave resonator of the first filter
136A can maintain and/or increase a reflection coefficient of the
first filter 136A in the second passband of the second filter 136B
that is associated with the second carrier of the carrier
aggregation signal.
The filters 136B to 136N of the multiplexer 135 can include one or
more acoustic wave filters, one or more acoustic wave filters that
include at least one bulk acoustic wave resonator with a
multi-layer raised frame structure, one or more LC filters, one or
more hybrid acoustic wave LC filters, or any suitable combination
thereof.
The multi-layer raised frame bulk acoustic wave resonators
disclosed herein can be implemented in a variety of packaged
modules. Some example packaged modules will now be discussed in
which any suitable principles and advantages of the bulk acoustic
wave devices disclosed herein can be implemented. The example
packaged modules can include a package that encloses the
illustrated circuit elements. The illustrated circuit elements can
be disposed on a common packaging substrate. The packaging
substrate can be a laminate substrate, for example. FIGS. 14, 15A,
15B, and 16 are schematic block diagrams of illustrative packaged
modules according to certain embodiments. Certain example packaged
modules include one or more radio frequency amplifiers, such as one
or more power amplifiers and/or one or more low noise amplifiers.
Any suitable combination of features of these modules can be
implemented with each other. While duplexers are illustrated in the
example packaged modules of FIGS. 14, 15A, and 16, any other
suitable multiplexer that includes a plurality of acoustic wave
filters coupled to a common node can be implemented instead of one
or more duplexers. For example, a quadplexer can be implemented in
certain applications. Alternatively or additionally, one or more
filters of a packaged module can be arranged as a transmit filter
or a receive filter that is not included in a multiplexer.
FIG. 14 is a schematic block diagram of a module 140 that includes
duplexers 141A to 141N and an antenna switch 142. One or more
filters of the duplexers 141A to 141N can include any suitable
number of multi-layer raised frame bulk acoustic wave resonators in
accordance with any suitable principles and advantages discussed
herein. Any suitable number of duplexers 141A to 141N can be
implemented. The antenna switch 142 can have a number of throws
corresponding to the number of duplexers 141A to 141N. The antenna
switch 142 can electrically couple a selected duplexer to an
antenna port of the module 140.
FIG. 15A is a schematic block diagram of a module 150 that includes
a power amplifier 152, a radio frequency switch 154, and duplexers
141A to 141N in accordance with one or more embodiments. The power
amplifier 152 can amplify a radio frequency signal. The radio
frequency switch 154 can be a multi-throw radio frequency switch.
The radio frequency switch 154 can electrically couple an output of
the power amplifier 152 to a selected transmit filter of the
duplexers 141A to 141N. One or more filters of the duplexers 141A
to 141N can include any suitable number of multi-layer raised frame
bulk acoustic wave resonators in accordance with any suitable
principles and advantages discussed herein. Any suitable number of
duplexers 141A to 141N can be implemented.
FIG. 15B is a schematic block diagram of a module 155 that includes
filters 156A to 156N, a radio frequency switch 157, and a low noise
amplifier 158 according to an embodiment. One or more filters of
the filters 156A to 156N can include any suitable number of
multi-layer raised frame bulk acoustic wave resonators in
accordance with any suitable principles and advantages disclosed
herein. Any suitable number of filters 156A to 156N can be
implemented. The illustrated filters 156A to 156N are receive
filters. In some embodiments (not illustrated), one or more of the
filters 156A to 156N can be included in a multiplexer that also
includes a transmit filter. The radio frequency switch 157 can be a
multi-throw radio frequency switch. The radio frequency switch 157
can electrically couple an output of a selected filter of filters
156A to 156N to the low noise amplifier 157. In some embodiments
(not illustrated), a plurality of low noise amplifiers can be
implemented. The module 155 can include diversity receive features
in certain applications.
FIG. 16 is a schematic block diagram of a module 160 that includes
a power amplifier 152, a radio frequency switch 154, and a duplexer
141 that includes a multi-layer raised frame bulk acoustic wave
device in accordance with one or more embodiments, and an antenna
switch 142. The module 160 can include elements of the module 140
and elements of the module 150.
One or more filters with any suitable number of multi-layer raised
frame bulk acoustic devices can be implemented in a variety of
wireless communication devices. FIG. 17A is a schematic block
diagram of a wireless communication device 170 that includes a
filter 173 with one or more multi-layer raised frame bulk acoustic
wave resonators in accordance with any suitable principles and
advantages disclosed herein. The wireless communication device 170
can be any suitable wireless communication device. For instance, a
wireless communication device 170 can be a mobile phone, such as a
smart phone. As illustrated, the wireless communication device 170
includes an antenna 171, a radio frequency (RF) front end 172 that
includes filter 173, an RF transceiver 174, a processor 175, a
memory 176, and a user interface 177. The antenna 171 can transmit
RF signals provided by the RF front end 172. The antenna 171 can
provide received RF signals to the RF front end 172 for
processing.
The RF front end 172 can include one or more power amplifiers, one
or more low noise amplifiers, RF switches, receive filters,
transmit filters, duplex filters, filters of a multiplexer, filters
of a diplexers or other frequency multiplexing circuit, or any
suitable combination thereof. The RF front end 172 can transmit and
receive RF signals associated with any suitable communication
standards. Any of the multi-layer raised frame bulk acoustic wave
resonators disclosed herein can be implemented in filters 173 of
the RF front end 172.
The RF transceiver 174 can provide RF signals to the RF front end
172 for amplification and/or other processing. The RF transceiver
174 can also process an RF signal provided by a low noise amplifier
of the RF front end 172. The RF transceiver 174 is in communication
with the processor 175. The processor 175 can be a baseband
processor. The processor 175 can provide any suitable base band
processing functions for the wireless communication device 170. The
memory 176 can be accessed by the processor 175. The memory 176 can
store any suitable data for the wireless communication device 170.
The processor 175 is also in communication with the user interface
177. The user interface 177 can be any suitable user interface,
such as a display.
FIG. 17B is a schematic diagram of a wireless communication device
180 that includes filters 173 in a radio frequency front end 172
and second filters 183 in a diversity receive module 182. The
wireless communication device 180 is like the wireless
communication device 170 of FIG. 17A, except that the wireless
communication device 180 also includes diversity receive features.
As illustrated in FIG. 17B, the wireless communication device 180
includes a diversity antenna 181, a diversity module 182 configured
to process signals received by the diversity antenna 181 and
including filters 183, and a transceiver 174 in communication with
both the radio frequency front end 172 and the diversity receive
module 182. One or more of the second filters 183 can include a
bulk acoustic wave resonator with a multi-layer raised frame
structure in accordance with any suitable principles and advantages
disclosed herein.
Bulk acoustic wave devices disclosed herein can be included in a
filter and/or a multiplexer arranged to filter a radio frequency
signal in a fifth generation (5G) New Radio (NR) operating band
within Frequency Range 1 (FR1). FR1 can from 410 megahertz (MHz) to
7.125 gigahertz (GHz), for example, as specified in a current 5G NR
specification. A filter arranged to filter a radio frequency signal
in a 5G NR FR1 operating band can include one or more bulk acoustic
wave resonators be implemented in accordance with any suitable
principles and advantages disclosed herein.
5G NR carrier aggregation specifications can present technical
challenges. For example, 5G carrier aggregations can have wider
bandwidth and/or channel spacing than fourth generation (4G) Long
Term Evolution (LTE) carrier aggregations. Carrier aggregation
bandwidth in certain 5G FR1 applications can be in a range from 120
MHz to 400 MHz, such as in a range from 120 MHz to 200 MHz. Carrier
spacing in certain 5G FR1 applications can be up to 100 MHz. Bulk
acoustic wave resonators with a multi-layer raised frame structure
disclosed herein can achieve low insertion loss and low Gamma loss.
The frequency of a raised frame mode of such a bulk acoustic wave
resonator can be moved significantly away from a resonant frequency
of the bulk acoustic wave resonator. Accordingly, the raised frame
mode can be outside of a carrier aggregation band even with the
wider carrier aggregation bandwidth and/or channel spacing within
FR1 in 5G specifications. This can reduce and/or eliminate Gamma
degradation in an operating band of another carrier of a carrier
aggregation. In some instances, Gamma can be increased in the
operating band of the other carrier of the carrier aggregation.
Any of the embodiments described above can be implemented in
association with mobile devices such as cellular handsets. The
principles and advantages of the embodiments can be used for any
systems or apparatus, such as any uplink wireless communication
device, that could benefit from any of the embodiments described
herein. The teachings herein are applicable to a variety of
systems. Although this disclosure includes some example
embodiments, the teachings described herein can be applied to a
variety of structures. Any of the principles and advantages
discussed herein can be implemented in association with RF circuits
configured to process signals in a frequency range from about 30
kHz to 300 GHz, such as in a frequency range from about 450 MHz to
8.5 GHz.
Aspects of this disclosure can be implemented in various electronic
devices. Examples of the electronic devices can include, but are
not limited to, consumer electronic products, parts of the consumer
electronic products such as packaged radio frequency modules,
uplink wireless communication devices, wireless communication
infrastructure, electronic test equipment, etc. Examples of the
electronic devices can include, but are not limited to, a mobile
phone such as a smart phone, a wearable computing device such as a
smart watch or an ear piece, a telephone, a television, a computer
monitor, a computer, a modem, a hand-held computer, a laptop
computer, a tablet computer, a microwave, a refrigerator, a
vehicular electronics system such as an automotive electronics
system, a stereo system, a digital music player, a radio, a camera
such as a digital camera, a portable memory chip, a washer, a
dryer, a washer/dryer, a copier, a facsimile machine, a scanner, a
multi-functional peripheral device, a wrist watch, a clock, etc.
Further, the electronic devices can include unfinished
products.
Unless the context indicates otherwise, throughout the description
and the claims, the words "comprise," "comprising," "include,"
"including" and the like are to generally be construed in an
inclusive sense, as opposed to an exclusive or exhaustive sense;
that is to say, in the sense of "including, but not limited to."
Conditional language used herein, such as, among others, "can,"
"could," "might," "may," "e.g.," "for example," "such as" and the
like, unless specifically stated otherwise, or otherwise understood
within the context as used, is generally intended to convey that
certain embodiments include, while other embodiments do not
include, certain features, elements and/or states. The word
"coupled", as generally used herein, refers to two or more elements
that may be either directly connected, or connected by way of one
or more intermediate elements. Likewise, the word "connected", as
generally used herein, refers to two or more elements that may be
either directly connected, or connected by way of one or more
intermediate elements. Additionally, the words "herein," "above,"
"below," and words of similar import, when used in this
application, shall refer to this application as a whole and not to
any particular portions of this application. Where the context
permits, words in the above Detailed Description using the singular
or plural number may also include the plural or singular number
respectively.
While certain embodiments have been described, these embodiments
have been presented by way of example only, and are not intended to
limit the scope of the disclosure. Indeed, the novel resonators,
devices, modules, apparatus, methods, and systems described herein
may be embodied in a variety of other forms. Furthermore, various
omissions, substitutions and changes in the form of the resonators,
devices, modules, apparatus, methods, and systems described herein
may be made without departing from the spirit of the disclosure.
For example, while blocks are presented in a given arrangement,
alternative embodiments may perform similar functionalities with
different components and/or circuit topologies, and some blocks may
be deleted, moved, added, subdivided, combined, and/or modified.
Each of these blocks may be implemented in a variety of different
ways. Any suitable combination of the elements and/or acts of the
various embodiments described above can be combined to provide
further embodiments. The accompanying claims and their equivalents
are intended to cover such forms or modifications as would fall
within the scope and spirit of the disclosure.
* * * * *